Mahāśivarātri

1. १Step 1, Aṅga

   Caturdaśī runs from 17:10 on Thu 11 Mar to 17:33 on Fri 12 Mar.

   2021-03-11T09:10:18Z → 2021-03-12T09:33:02Z
2. २Step 2, Kāla

   Niśītha is 1 ghaṭikā either side of midnight: 00:39–01:27 on the 11th, 00:39–01:27 on the 12th.

   nishita: midnight-pm-1-ghatika · sunrise and sunset: upper limb, 31′ + 16′
3. ३Step 3, Rule

   Caturdaśī must be present during niśītha. It covers 48 of 48 minutes on the 11th and 0 of 48 on the 12th.

   Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 105
4. ४Step 4, Tie-break

   Only one night qualifies. No tie-break is needed.

   priority: disputed → only-day · margin 25568 s
5. ५Step 5, Ruling

   Mahāśivarātri, Chongqing, 2021: Thursday 11 March.

   confidence: determinate

In Chongqing, Mahāśivarātri 2021 falls on Thursday 11 March. Caturdaśī runs from 17:10 on Thu 11 Mar to 17:33 on Fri 12 Mar and covers all of niśītha that night.

Institutional rulings are recorded with a source address, and are never edited to agree.

Month

Māgha, amānta

Pakṣa · aṅga

Kṛṣṇa · Caturdaśī

Kāla

Niśītha

Priority

Disputed

Tie-break

Longer coverage, as a boundary

Reference

CRC 1955, p. 105

K 14 Mahasivaratri (nisithavyapini) — In some opinion it is to be observed on nisitha and in some opinion on pradosa. If occurs on two successive nisithas then according to Hemadri it is to be observed on the first day and according to Madhava, to be observed on the second day Calendar Reform Committee 1955, General Rules for Religious Festivals, p. 105.

The alternative opinion that reads pradoṣa instead of niśītha is not evaluated.